Since the advent of the graphical user interface (GUI) in the early 1980s, computers have employed, as user input devices, devices that allow a user to perform two basic functions, first, a two-dimensional movement function, such as moving a cursor around on a two-dimensional display, and, second, a pulsing or "clicking" function, that allows a user to select a function associated with a particular position on the display.
In a GUI, information displayed includes object symbols, such as windows, icons, slider bars, soft "buttons", etc. The two-dimensional movement function allows a user to move a cursor to an area of the screen within which a desired object symbol is located. The clicking function allows the user to select, operate, or manipulate the object symbols, and, in so doing, perform computer operations.
The number of such functions that a GUI supports is wide and varied. For instance, any window that shows a portion of an image (such as a word processor showing a portion of a lengthy document) provides for scrolling through the image. A slider bar is provided for this purpose. For incremental scrolling, the user moves the cursor to an up or down arrow, and holds a click button down to invoke the scrolling function. For long-distance moves, the user positions the cursor on a slider block, holds a click button down, and moves the mouse to drag the slider block along the slider bar. A portion of the image, in a position proportional to the position of the block along the slider bar, is displayed. This arrangement is both easy and intuitive for the user.
Other functions include the "drag and drop" function, similar to that used with the slider block, but applicable to icons and other objects in the GUI display.
As application software has increased in sophistication and "user-friendliness," more and more of the functionality of a computer has migrated from a typewriter-style keyboard to a user interface device providing this functionality.
The most commonly employed user input mechanism is a mouse. A mouse is a hand-held device having a surface contact member such as a ball. The user moves the mouse over a work surface such as a table top, causing the ball to roll. Sensors within the device detect the rolling, and translate it into two-dimensional movement signals analogous to the user's movement of the mouse. The signals are sent over a wire to a computer, in accordance with a known mouse interface protocol. The computer runs a mouse driver application, which interprets the movement signals and directs the movement, on the GUI, of a symbol such as a cursor. The mouse also has click buttons, preferably two, which are positioned so that the user can conveniently press the buttons with his/her fingers, without having to change the grip on the mouse.
Computer software, in the form of "mouse driver" programs, have been employed along with these physical apparatus. A mouse driver essentially receives signals through a mouse interface (typically a serial cable), interprets the signals in terms of movement (two dimensions, in the plus and minus directions each) and selection (mouse button clicking), and directs the operating system and/or application programs to perform a desired function.
A major advance was made when IBM Corporation developed the TrackPoint II.TM. and TrackPoint III.TM. pointing device (hereinafter generally referred to as "TrackPoint devices"). A TrackPoint device includes a small, joystick-like member which is mounted in a keyboard, between the keys. Click buttons are provided on the keyboard also, preferably centered and in front of a space bar.
The TrackPoint device enhanced the portability of small, laptop computers, because all the functionality of a mouse fit within the keyboard. It was not necessary to carry the mouse separately, or to find a flat surface for using the mouse.
However, because graphical user interfaces are so powerful, more sophisticated ways of exploiting the user interface capabilities have been pursued. For instance, since GUI applications provide scrolling functions as well as symbol selection functions, and since functions both inside an application and outside on the desktop/operating system employ selection functions, it is likely to be a convenience for the user to have multiple cursor manipulation apparatus.
To further expand the capabilities of a user interface device for use with a GUI computer, mice have had added apparatus to provide, in effect, a Z axis of movement, to go along with the X and Y axes of movement provided by ordinary mice. For instance, in U.S. Pat. No. 5,530,455, Gillick et al., "Roller Mouse for Implementing Scrolling in Windows Applications" and U.S. Pat. No. 5,446,481, Gillick et al., :Multidimensional Hybrid Mouse for Computers", a Z axis roller is added.
However, these additional features are limited in their use, since they are useful only for tasks for which one additional dimension is needed.
IBM Corp. has developed a keyboard with two TrackPoint devices, positioned at two different sites within the keyboard. Because there are two such devices, each having full two-dimensional capability, added functionality and flexibility are realized.
Accordingly, the user, when choosing a type of interface device to use, has many options. In fact, a user's manual dexterity is capable of making effective use of a plurality of such devices. However, heretofore, GUI software has been limited in its ability to support user commands. For instance, in a word processor, a user must use the same cursor, and the same interface mechanism, for scrolling through a document, selecting text for cutting and pasting, etc. Also, if the user is both operating an application and moving or invoking objects on the desktop, the same cursor and interface device are again used. Therefore, conventional GUI software and interface device drivers have had the drawback of limiting the user's efficiency and productivity by not allowing users to take full advantage of the graphical user interface's capacity to perform quick and convenient functions, responsive to user commands.